1. Field of the Invention
This invention relates to control dampers for heating, ventilation and air conditioning systems. More particularly, this invention relates to motorized control dampers having one or more damper blades movable between opened and closed positions.
2. Description of the Background Art
Heating, ventilating and air conditioning (HVAC) systems are typically zoned to direct the air flow to selected portions of a building. More particularly, zoned HVAC Systems typically utilize control dampers positioned in the duct work to selectively allow or prevent air flow through the duct to the zone of the building being served by such duct. The use of such control dampers allow one HVAC systems to selectively heat or cool the various zones of the building thereby eliminating the need for separate HVAC systems.
Control dampers usually comprise a substantially rectangular frame work having one or more damper blades positioned from side to side. Either a manual crank or a motor is operatively connected to one of the damper blades so as to move the blade between an obstructing, closed position and a substantially non-obstructing, opened position. Mechanical linkages are typically provided to also mechanically operates the other damper blades simultaneous with the damper blade being driven by the crank or motor.
In many applications, it is desired for motorized control dampers to be either normally opened or normally closed. Typically, the motor operatively connected to the driven damper blade functions to drive the blade from its normally closed or open position to the other position. Then, upon the deenergizing of the motor, the damper blades return to their normal position by means of a return spring mounted within or approximate to the motor.
Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the motorized control damper art.
Another object of this invention is to provide a motorized control damper having an improved return spring which functions to return the damper blades to their normal position, either closed or opened.
Another object of this invention is to provide a motorized control damper having an improved return spring so positioned relative to the damper blade being driven that such blade is promptly returned to its normal position, either opened or closed.
Another object of this invention is to provide a motorized control damper having a return spring which is positioned concentrically relative to the drive shaft of the damper blade being driven so as to exert adequate force on the drive shaft to return the damper blade being driven, and in the other damper blades mechanically linked thereto, to their normally opened or closed positions.
Another object of this invention is to provide a motorized control damper having a return spring mounted concentrically with the drive shaft of the damper blade being driven on the side of the damper opposite that to the motor such that the output shaft of the motor can be directly connected to the drive shaft at one side of the damper and the return spring connected to the other end of the drive shaft on the other side of the damper allowing the control damper to be easily mounted within an existing duct.
The forgoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.